QUANTUM OSCILLATIONS IN MESOSCOPIC RINGS WITH MANY CHAINS

We obtain exact analytical expressions for the electronic transport th rough a multichain system, also in the presence of magneto-and electro static fields. The geometrical structure of the electrodes is found to cause a splitting of the conduction band into many subbands depending on the number and the length of the chains, and the conductance appro aches zero when the chain number is sufficiently large due to quantum interference. In the presence of a magnetic field very complicated osc illatory behavior of the conductance is found with a very sensitive de pendence on the number of chains and their lengths, in a remarkable di stinction from the usual two-chain Aharonov-Bohm (AB) ring. A transver se electric bias is found to cause oscillations of the conductance and by increasing the chain number the widths of the resonance peaks beco me narrower without a change of the oscillation periodicities. If elec tric and magnetic fields are simultaneously applied the magnetoconduct ance oscillation pattern depends sensitively on the bias. The present study may provide useful information for quantum device engineering.